Voting For a Cartel as a Sign of Cooperativeness

This paper tests the hypothesis that a (partial) reason why cartels – costly non-binding price agreements – lead to higher prices in Bertrand Pricing Game-experiments could be because participants who form these kinds of agreements are more cooperative and pick higher numbers in general. To test this hypothesis we run an experiment where participants play two consecutive Bertrand oligopoly games: first a standard version without the opportunity to make price agreements; followed by a version where participants can vote, by majority, on whether to have a costly nonbinding agreement to pick the highest number. We find no statistically significant difference between the numbers picked in the first game by participants who vote for and against an agreement in the second game. We do confirm that having a price agreement leads to higher numbers being picked on average. Additionally we find that participants who vote for or against the price-agreement behave differently in response to the existence of the price agreement. In particular, participants who vote for a price agreement react more positively to the price agreement. The difference in numbers picked in the second game between situations with and without a price agreement is larger for participants who voted in favour of the agreement. Voters who voted for the price agreement are more cooperative than voters who voted against but only in situations where there is a price agreement.